Led by Executive Chairman and CEO Nicholas Schorsch, ARCP said last week it expects to reach its investment goal of $3 billion for the entire year with the Red Lobster purchase. As a result, the company is raising its acquisitions target for 2014 to $4.5 billion.

The shopping center properties are the same assets ARCP slated in March to be spun off into a new REIT called American Realty Capital Centers, Inc.

However, Schorsch said the plan to spin-off the retail portfolio prompted inquiries from investors and new options -- along with an opportunity to simplify ARCP, which over the last year has grown into the largest U.S. owner of single-tenant real estate.

"We now believe the sale of the multi-tenant portfolio will deliver the best value creation option to our shareholders and serve to enhance the clarity of our single-tenant, net lease investment strategy," Schorsch said in a statement.

ARCP President David S. Kay said the Blackstone sale will allow the company to fund the Red Lobster purchase by selling the shopping center portfolio at a capitalization rate more than 100 basis points below the 7.9% cash cap rate to be paid for the Red Lobster portfolio.

ARCP's shares fell nearly 5% to a one-year low of $12.26 at the close of trading Wednesday after the company issued a separate announcement that it will issue 100 million common shares. The stock has fallen more than 15.5% since the mid-March announcement of the planned spin-off of its multi-tenant portfolio.